That formula is correct, your logic isn't. What I've been saying in multiple posts, and what you're not grasping, is that the volume (or air mass) increases with a larger turbo at the same boost pressure

Lol, disregard the size of the turbocharger. The volume in the intake manifold/cylinder head ports remains the same. So the only way to get more mass is to increase pressure or decrease temperature (very likely the main piece that adds power if pressure remains the same). You may get more flow from the compressor but you are still forcing the air into the same amount of space (volume).